LeetCode精华题目列表【刷题规划系列】

题目的颜色代表难度：绿色-简单，橙色-中等，红色-难，粉色-极难/Tricky

Basic Data Structures

Array

Classic Problems	Similar Problems
189. Rotate Array
88. Merge Sorted Array
1260. Shift 2D Grid
941. Valid Mountain Array
283. Move Zeros
167. Two Sum II – Input array is sorted
167. Two Sum II – Input array is sorted
26. Remove Duplicates from Sorted Array	80. Remove Duplicates from Sorted Array II
56. Merge Intervals
11. Container With Most Water
31. Next Permuation
442. Find All Duplicates in an Array
48. Rotate Image
75. Sort Colors
57. Insert Interval
42. Trapping Rain Water

String

Classic Problems	Similar Problems
551. Student Attendance Record I
344. Reverse String
937. Reorder Data in Log Files
824. Goat Latin
415. Add Strings
14. Longest Common Prefix
28. Implement strStr()
6. ZigZag Conversion
8. String to Integer (atoi)
443. String Compression
151. Reverse Words in a String	186. Reverse Words in a String II	557. Reverse Words in a String III
809. Expressive Words
616. Add Bold Tag in String
848. Shifting Letters
68. Text Justification
1328. Break a Palindrome

Linked List

Classic Problems	Similar Problems
876. Middle of the Linked List
21. Merge Two Sorted Lists
237. Delete Node in a Linked List
206. Reverse Linked List	92. Reverse Linked List II	24. Swap Nodes in Pairs	25. Reverse Nodes in k-Group
234. Palindrome Linked List
83. Remove Duplicates from Sorted List	82. Remove Duplicates from Sorted List II
141. Linked List Cycle	142. Linked List Cycle II
2. Add Two Numbers	445. Add Two Numbers II
19. Remove Nth Node From End of List
708. Insert into a Sorted Circular Linked List
147. Insertion Sort List
725. Split Linked List in Parts

Queue

Classic Problems	Similar Problems
346. Moving Average from Data Streamy
225. Implement Stack using Queues
622. Design Circular Queue

Stack

Classic Problems	Similar Problems
22. Valid Parentheses
1249.Minimum Remove to Make Valid Parentheses
1021. Remove Outermost Parentheses
232. Implement Queue using Stacks
682. Baseball Game
155. Min Stack
496. Next Greater Element I	503. Next Greater Element II	739. Daily Temperatures	1019. Next Greater Node In Linked List
1249. Minimum Remove to Make Valid Parentheses
173. Binary Search Tree Iterator
636. Exclusive Time of Functions
394. Decode String	224. Basic Calculator
71. Simplify Path
735. Asteroid Collision
150. Evaluate Reverse Polish Notation
32. Longest Valid Parentheses
84. Largest Rectangle in Histogram	85. Maximal Rectangle
895. Maximum Frequency Stack

Advanced Data Structures

HashSet / HashTable

Classic Problems	Similar Problems
1. Two Sum	15. 3Sum	18. 4Sum
349. Intersection of Two Arrays
953. Verifying an Alien Dictionary
359. Logger Rate Limiter
1002. Find Common Characters
811. Subdomain Visit Count
3. Longest Substring Without Repeating Characters
560. Subarray Sum Equals K	974. Subarray Sums Divisible by K
380. Insert Delete GetRandom O(1)
49. Group Anagrams	438. Find All Anagrams in a String
138. Copy List with Random Pointer	133. Clone Graph
166. Fraction to Recurring Decimal
356. Line Reflection
535. Encode and Decode TinyURL
554. Brick Wall
966. Vowel Spellchecker
340. Longest Substring with At Most K Distinct Characters
76. Minimum Window Substring

Tree

Classic Problems	Similar Problems
543. Diameter of Binary Tree	124. Binary Tree Maximum Path Sum
226. Invert Binary Tree
104. Maximum Depth of Binary Tree	559. Maximum Depth of N-ary Tree
101. Symmetric Tree
108. Convert Sorted Array to Binary Search Tree
112. Path Sum	113. Path Sum II	437. Path Sum III
105. Construct Binary Tree from Preorder and Inorder Traversal		1008. Construct Binary Search Tree from Preorder Traversal	889. Construct Binary Tree from Preorder and Postorder Traversal
98. Validate Binary Search Tree
236. Lowest Common Ancestor of a Binary Tree
103. Binary Tree Zigzag Level Order Traversal
199. Binary Tree Right Side View
987. Vertical Order Traversal of a Binary Tree
114. Flatten Binary Tree to Linked List
979. Distribute Coins in Binary Tree
116. Populating Next Right Pointers in Each Node	117. Populating Next Right Pointers in Each Node II
1123. Lowest Common Ancestor of Deepest Leaves
337. House Robber III
450. Delete Node in a BST
297. Serialize and Deserialize Binary Tree	449. Serialize and Deserialize BST	428. Serialize and Deserialize N-ary Tree
968. Binary Tree Cameras

Heap

Classic Problems	Similar Problems
703. Kth Largest Element in a Stream	215. Kth Largest Element in an Array	692. Top K Frequent Words	1387. Sort Integers by The Power Value
253. Meeting Rooms II
373. Find K Pairs with Smallest Sums
973. K Closest Point to Origin
767. Reorganize String
378. Kth Smallest Element in a Sorted Matrix
264. Ugly Number II
358. Rearrange String k Distance Apart
23. Merge k Sorted Lists
295. Find Median from Data Stream
407. Trapping Rain Water II
818. Race Car

Graph (Breadth-FS)

Classic Problems	Similar Problems
310. Minimum Height Trees
1162. As Far from Land as Possible
934. Shortest Bridge
542. 01 Matrix
1129. Shortest Path with Alternating Colors

Graph (Best-FS)

Classic Problems	Similar Problems
743. Network Delay Time
1102. Path With Maximum Minimum Value
787. Cheapest Flights Within K Stops

Graph (DFS)

Classic Problems	Similar Problems
332. Reconstruct Itinerary
200. Number of Islands	305. Number of Islands II
694. Number of Distinct Islands
785. Is Graph Bipartite?	886. Possible Bipartition
399. Evaluate Division
261. Graph Valid Tree
841. Keys and Rooms
1059. All Paths from Source Lead to Destination
417. Pacific Atlantic Water Flow

Basic Algorithms

Binary Search

Classic Problems	Similar Problems
69. Sqrt(x)	50. Pow(x, n)
852. Peak Index in a Mountain Array	162. Find Peak Element	1095. Find in Mountain Array
704. Binary Search	34. Find First and Last Position of Element in Sorted Array
29. Divide Two Integers
33. Search in Rotated Sorted Array	81. Search in Rotated Sorted Array II
153. Find Minimum in Rotated Sorted Array	154. Find Minimum in Rotated Sorted Array II
74. Search a 2D Matrix
875. Koko Eating Bananas	1062. Longest Repeating Substring	1011. Capacity To Ship Packages Within D Days	1292. Maximum Side Length of a Square with Sum Less than or Equal to Threshold
	1231. Divide Chocolate	410. Split Array Largest Sum
4. Median of Two Sorted Arrays
528. Random Pick with Weight
1055. Shortest Way to Form String

Breadth-First Search

Classic Problems	Similar Problems
339. Nested List Weight Sum	364. Nested List Weight Sum II
994. Rotting Oranges
127. Word Ladder	126. Word Ladder II
863. All Nodes Distance K in Binary Tree
909. Snakes and Ladders
967. Numbers With Same Consecutive Differences
752. Open the Lock
675. Cut Off Trees for Golf Event
773. Sliding Puzzle

Best-First Search

Classic Problems	Similar Problems
505. The Maze II
264. Ugly Number II
818. Race Car
871. Minimum Number of Refueling Stops
778. Swim in Rising Water

Depth-First Search

Classic Problems	Similar Problems
733. Flood Fill
439. Ternary Expression Parser
394. Decode String	224. Basic Calculator
1376. Time Needed to Inform All Employees
490. The Maze
679. 24 Game
1377. Frog Position After T Seconds
827. Making A Large Island

Backtracking

Classic Problems	Similar Problems
22. Generate Parentheses
78. Subsets	90. Subsets II
39. Combination Sum	40. Combination Sum II
46. Permutations	77. Combinations
17. Letter Combinations of a Phone Number
491. Increasing Subsequences
1087. Brace Expansion	1096. Brace Expansion II
489. Robot Room Cleaner
753. Cracking the Safe
1240. Tiling a Rectangle with the Fewest Squares

Dynamic Programming 1D

Classic Problems	Similar Problems
303. Range Sum Query – Immutable
53. Maximum Subarray
70. Climbing Stairs
198. House Robber
91. Decode Ways
139. Word Break	140. Word Break II
300. Longest Increasing Subsequence
279. Perfect Squares
96. Unique Binary Search Trees	95. Unique Binary Search Trees II
1048. Longest String Chain
338. Counting Bits
413. Arithmetic Slices
343. Integer Break
1186. Maximum Subarray Sum with One Deletion

Dynamic Programming 1D (Multiple States)

Classic Problems	Similar Problems
256. Paint House
309. Best Time to Buy and Sell Stock with Cooldown	714. Best Time to Buy and Sell Stock with Transaction Fee
213. House Robber II
801. Minimum Swaps To Make Sequences Increasing
978. Longest Turbulent Subarray
790. Domino and Tromino Tiling
552. Student Attendance Record II

Dynamic Programming 2D (2D Input)

Classic Problems	Similar Problems
304. Range Sum Query 2D – Immutable
64. Minimum Path Sum
120. Triangle
62. Unique Paths	63. Unique Paths II
85. Maximal Rectangle
312. Burst Balloons
410. Split Array Largest Sum
1074. Number of Submatrices That Sum to Target

Dynamic Programming 2D (Two 1D Inputs)

Classic Problems	Similar Problems
1143. Longest Common Subsequence	115. Distinct Subsequences
712. Minimum ASCII Delete Sum for Two Strings
72. Edit Distance
10. Regular Expression Matching	44. Wildcard Matching
97. Interleaving String

Dynamic Programming 2D (1D Input)

Classic Problems	Similar Problems
5. Longest Palindromic Substring	516. Longest Palindromic Subsequence	1312. Minimum Insertion Steps to Make a String Palindrome	1216. Valid Palindrome III
1027. Longest Arithmetic Subsequence
877. Stone Game
873. Length of Longest Fibonacci Subsequence
1246. Palindrome Removal

Dynamic Programming 2D (1D Input + K)

Classic Problems	Similar Problems
265. Paint House II
123. Best Time to Buy and Sell Stock III	188. Best Time to Buy and Sell Stock IV

Dynamic Programming (Knapsack)

Classic Problems	Similar Problems
322. Coin Change
377. Combination Sum IV
416. Partition Equal Subset Sum
474. Ones and Zeroes

Advanced Algorithms

Trie

Classic Problems	Similar Problems
720. Longest Word in Dictionary	208. Implement Trie (Prefix Tree)	211. Design Add and Search Words Data Structure	642. Design Search Autocomplete System

Union Find

Classic Problems	Similar Problems
547. Friend Circles	721. Accounts Merge	323. Number of Connected Components in an Undirected Graph	684. Redundant Connection
	737. Sentence Similarity II	924. Minimize Malware Spread

Topological Sort

Classic Problems	Similar Problems
207. Course Scheduley	210. Course Schedule II	802. Find Eventual Safe States	269. Alien Dictionary

Boyer-Moore Voting Algorithm

Classic Problems	Similar Problems
169. Majority Element	229. Majority Element II	159. Longest Substring with At Most Two Distinct Characters	1157. Online Majority Element In Subarray

Complex Problems

HashTable + Doubly Linked List

Classic Problems	Similar Problems
146. LRU Cache	460. LFU Cache